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Spathe A.,Max Planck Institute for Chemical Ecology | Reinecke A.,Max Planck Institute for Chemical Ecology | Reinecke A.,Max Planck Institute for Ornithology (Seewiesen) | Olsson S.B.,Max Planck Institute for Chemical Ecology | And 4 more authors.
Chemical Senses | Year: 2013

The reproductive success of herbivorous insects largely depends on the mother's oviposition preference. In nocturnal insects, olfaction is arguably the most important sensory modality mediating mate finding, foraging, and host location. In most habitats, gravid females select among a number of plants of varying suitability, yet assessment of the neuroethological mechanisms underlying odor-guided choice between host plants is rare. Using a series of behavioral, electrophysiological, and chromatographic analyses in the Hawk moth, Manduca sexta, we show that gravid females perform a hierarchical choice among host plants of different species and qualities using olfactory cues. Both relevant plant species and qualities can be distinguished by volatile profiles collected from the headspace of these plants, and olfactory sensilla on female antennae detect more than half of the about 120 analytically detected volatiles in host plant headspace samples. Although olfactory sensory neurons present in antennal sensilla are mainly broadly tuned to multiple host compounds, some sensilla exhibit species and condition-specific responses. In fact, species and quality can be distinguished by the physiologically active components alone. Our findings thus suggest that distinguishing characteristics of both host species and quality are already represented at the sensory periphery. © The Author 2012. Published by Oxford University Press. All rights reserved. Source


Kumar S.N.,Central Plantation Crops Research Institute | Kumar S.N.,Indian Agricultural Research Institute
Journal of Agricultural and Food Chemistry | Year: 2011

Coconut oil, the main product of coconut fruit, is the richest source of glycerol and lauric acid and hence is called lauric oil. This paper reports the fatty acid profile of oil from 60 Talls, 14 Dwarfs, and 34 hybrids. These include collections from 13 countries covering a large coconut-growing area of the world, apart from the indigenous ones. Capillary gas chromatography analysis of oil indicated a wider variation for the fatty acid profile than earlier reported. Apart from this, for the first time other fatty acids such as behenic and lignoceric acids were detected. Oil from cultivars and hybrids of coconut has significantly differed, particularly for commercially important fatty acids such as lauric acid and unsaturated fatty acids. However, coconut oil seems to have a conserved fatty acid profile, mainly because of low unsaturated fatty acids, indicating the possibility of grouping cultivars on the basis of their fatty acid profiles. The cluster analysis based on fatty acid profile indicated grouping together of geographically and typically closely related cultivars. Cultivars with high concentrations of specific fatty acids can be of potential use for industrial exploitation, whereas those with high concentrations of short- and medium-chain fatty acids and unsaturated fatty acids are more suitable for human consumption. Cultivars and hybrids with high and low values for each of the fatty acids are also identified. © 2011 American Chemical Society. Source


Hebbar K.B.,Central Institute for Cotton Research | Hebbar K.B.,Central Plantation Crops Research Institute | Venugopalan M.V.,Central Institute for Cotton Research | Prakash A.H.,Central Institute for Cotton Research | Aggarwal P.K.,Indian Agricultural Research Institute
Climatic Change | Year: 2013

General circulation models (GCMs) project increases in the earth's surface air temperatures and other climate changes by the mid or late 21st century, and therefore crops such as cotton (Gossypium spp L.) will be grown in a much different environment than today. To understand the implications of climate change on cotton production in India, cotton production to the different scenarios (A2, B2 and A1B) of future climate was simulated using the simulation model Infocrop-cotton. The GCM projections showed a nearly 3.95, 3.20 and 1.85 °C rise in mean temperature of cotton growing regions of India for the A2, B2 and A1B scenarios, respectively. Simulation results using the Infocrop-cotton model indicated that seed cotton yield declined by 477 kg ha-1 for the A2 scenario and by 268 kg ha-1 for the B2 scenario; while it was non-significant for the A1B scenario. However, it became non-significant under elevated [CO2] levels across all the scenarios. The yield decline was higher in the northern zone over the southern zone. The impact of climate change on rainfed cotton which covers more than 60 % of the country's total cotton production area (mostly in the central zone) and is dependent on the monsoons is likely to be minimum, possibly on account of marginal increase in rainfall levels. Results of this assessment suggest that productivity in northern India may marginally decline; while in central and southern India, productivity may either remain the same or increase. At the national level, therefore, cotton production is unlikely to change with climate change. Adaptive measures such as changes in planting time and more responsive cultivars may further boost cotton production in India. © 2013 Springer Science+Business Media Dordrecht. Source


Sujatha S.,Central Plantation Crops Research Institute | Bhat R.,Central Plantation Crops Research Institute
Communications in Soil Science and Plant Analysis | Year: 2012

A field experiment (1998 to 2010) investigated the effects of vermicompost (VC) and chemical fertilizer (CF) application alone or in combination on soil fertility status in arecanut. Vermicompost significantly increased the soil pH (6.3) over CF and integrated treatments (5.7-5.8). Greater soil organic carbon was noticed with VC (2.85-3.00%) than with CF (1.72-1.89%) and VC + CF (1.89-2.55%) in 2009. Soil test phosphorus (P) (mg kg-1) significantly increased with VC 200% nitrogen (N) equivalency (35.3) compared to other treatments (8.5-23.3) at the 0- to 30-cm depth in 2009. In 2003, soil test potassium (K) (mg kg-1) was significantly greater with CF at depths of both 0-30 cm (162-187) and 30-60 cm (172-214) than VC and control. Soil test K depleted with VC application in 2009. Application of VC significantly improved soil test calcium (Ca) and magnesium (Mg) compared to CF, CF + VC, and control at 0-30 cm deep. Soil test values for micronutrients increased in 2009 compared to initial status. © 2012 Copyright Taylor and Francis Group, LLC. Source


Bhat R.,Central Plantation Crops Research Institute | Sujatha S.,Central Plantation Crops Research Institute
Journal of Plant Nutrition | Year: 2013

Critical and optimum leaf nutrient standards for arecanut are unknown. As nutrients are becoming yield limiting factors in arecanut, corrective measures require development of leaf nutritional standards. The objective of this paper was to determine optimum concentration and range of all nutrients through boundary line approach. Optimum foliar concentrations for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) were established as 2.70, 0.23, 1.12, 0.61, and 0.20%, respectively, using leaf composition data from 12-year old arecanut plantation. Optima of major nutrient concentrations were nearly identical between boundary line approach and mean of high yielding population. Optimum micronutrient concentrations (mg kg-1) were estimated at 146 for iron (Fe), 56.5 for manganese (Mn), 2.6 for copper (Cu), 45.8 for zinc (Zn), 39.5 for boron (B), 432 for aluminum (Al) and 63 for sodium (Na). Optimum ranges and ratios of different nutrients were found out from second degree polynomial equations. © 2013 Copyright Taylor and Francis Group, LLC. Source

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